in what sense does it relies on "religion" (and which religion) to "you may sustain your life by killing and eating animals, AND by killing and using their organs if you garbaged yours (which you should avoid anyways)" which is reasoned with nature's observed behaviur of each species seem to absolutely protect their own at the expense of other species? exception are just those, exceptions. but the overarching rule is to be "selfish". if there would be any religion which contradict this is Christianity which teaches that you are not only should sustain you and your family/tribe/species but also the whole Earth, animals, plants we are entrusted with; so preferencing our own species is not absolute.